The invention relates to a method for adjusting a weighing apparatus, wherein a weight indicated by the weighing apparatus is adapted to a gravity prevailing at the placement location of the weighing apparatus.
Such weighing apparatus are typically constructed as scales and can be used for weighing persons or objects. In the case of scales which are used in the medical field, an adjustment and possibly a calibration are necessary.
The weight indicated by the scale is dependent upon the mass of the object to be weighed, as well as on the local Earth's gravity. In this connection, the Earth's gravity is not constant at all locations of the Earth's surface, but varies locally to an extent that deviations within the intended measurement resolution for the weight occur.
In accordance with the state of the art, the Earth's gravity prevailing at the intended placement location can be taken into consideration by various measures. On the one hand, it is possible to carry out an individual manufacture of the scale taking into consideration the intended placement location. This results in comparatively high manufacturing costs. In accordance with another variation, it is possible to manufacture the scale in accordance with a predetermined standard and once again to adjust, and possibly calibrate, the scale at the actual location of operation. This results in high costs for the user of the scale and frequently in long delays to start operation of the scale.
In accordance with an automated method, it is known to equip the scale with a GPS receiver and to thereby determine the actual placement location. The local Earth's gravity can then be determined in accordance with an approximation formula, or can be read from a stored table. This method also results in high manufacturing costs and requires the possibility of setting up a satellite connection.
In accordance with a simpler method, the geographic position is entered manually and the local Earth's gravity is computed through an approximation formula. In the case of input errors, this method results in incorrect measurements and, moreover, makes possible intentional manipulations of the indicated values. Accordingly, a use under calibrating conditions is not possible.
When data concerning the placement location and a subsequent computation of the Earth's gravity with the use of an approximation formula are scanned in, as is also conceivable, the same disadvantages occur as for the manual input already discussed above.